I.c. engine fuel rail assembly including a fuel separation membrane

摘要

A fuel rail assembly for supplying pressurized fuel to a plurality of cylinders of an engine includes a fuel rail housing 132 defining an internal fuel rail volume having at least a first region 133 and a second region 135 segregated by a fuel separation membrane element 134 disposed within the fuel rail housing 132. The membrane element can be configured to pass a first component of a fuel mixture such as an alcohol through the membrane element from the first region to the second region at a higher rate than a second component of the fuel mixture such as a hydrocarbon. The separated alcohol and hydrocarbon components can be provided to the engine in varying relative amounts based on operating conditions. A fuel mixture, eg of hydrocarbon (eg gasoline or diesel) and alcohol (eg ethanol or methanol) components, may be pumped from tank 120 to a fuel rail 130 which has a tubular fuel separation element 134 defining a region 135 separate from the outer fuel receiving region 133. The fuel separation element may be a selectively permeable membrane 134 permitting passage of the alcohol component, eg by pervaporation. The membrane may have a coating of polymer material or porous ceramic material, eg zirconia. The permeant vapour may be condensed for delivery via a separate fuel rail 160 or may be delivered as vapour to the intake manifold.